Even when mechanical component parts and the like are simple members, the required mechanical characteristics, functions and so forth often differ depending on sections. For example, when the shape is determined first in view of the installability and so on, there can be parts which can be of low strength and parts which can be of high strength. In this instance, if high-strength materials can be used for parts which can be of high strength and materials with good machinability and the like can be used for parts which can be of low strength, it is convenient because it is possible to expand the degree of freedom in designing, to reduce the weight, to improve the productivity, and so forth.
Moreover, when functions as structural materials are required on one of the opposite-end sides and functions such as a sliding property, wear resistance and heat resistance are required on the other one of the opposite-end sides, or when functions as magnetic materials are required on one of the opposite-end sides and functions as nonmagnetic materials are required on the other one of the opposite-end sides, if it is possible to produce multi-material segmented-part members comprising materials whose constituent compositions satisfy the respective requirements, it is preferable because it is possible to expand and the like the degree of freedom in designing and the functionality.
However, due to the convenience and the like in manufacturing, simple members so far have been basically formed of identical materials. In this case, the materials are determined by characteristics to which priority should be given, and the other required characteristics might often be sacrificed. If materials which satisfy both of the characteristics should have been used, such materials are expensive in general so that it is difficult to reduce the cost.
When different materials are cast around or deposited, or when partial heat treatments and the like are carried out, it is possible to provide simple members with different characteristics. However, the number of processes increases accordingly and the productivity degrades so that it is not possible to reduce the cost and so forth of the members.
It has been carried out to manufacture members by sintering compacts comprising powders whose constituent composition depends on sections. However, when powders whose constituent compositions differ are filled into a cavity at once, usually, a powder which exhibits high flowability is first filled thereinto, or a plurality of powders are disposed in a mixed manner. Hence, conventionally, the filling step has been carried out independently for each of powders whose constituent compositions differ, or preliminary compaction has been carried out every time one and only powder is filled thereinto and it has been carried out repeatedly, thereby manufacturing multi-material compacts.
Under such circumstances, it is needless to say that the man-hour requirements increase as described above and the productivity lowers so that it is difficult to reduce the cost of members.